Process for producing a biodegradable polymer

Abstract

A process for producing a biodegradable polymer, which comprises subjecting a cyclic compound of the following formula (1) or (2) to ring opening polymerization: ##STR1## wherein R 1 is a C 1-10 alkyl group, ##STR2## wherein R 2 is a C 1-10 alkyl group, and R 3 is a hydrogen atom or a C 1-10 alkyl group.

I claim: 
     
       1. A process for producing a biodegradable polymer, which comprises subjecting a cyclic compound of the following formula (1) or (2) to ring opening polymerization: ##STR8## wherein R 1  is a C 1-10  alkyl group, ##STR9## wherein R 2  is a C 1-10  alkyl group, and R 3  is a hydrogen atom or a C 1-10  alkyl group. 
     
     
       2. A cyclic compound of the formula (1): ##STR10## wherein R 1  is a C 1-10  alkyl group. 
     
     
       3. A process for producing a cyclic compound of the formula (1): ##STR11## wherein R 1  is a C 1-10  alkyl group, which comprises cyclically trimerizing a compound of the formula (3): ##STR12## wherein R 1  is as defined above and R 4  is a C 1-10  alkyl group, by an ester exchange catalyst. 
     
     
       4. A cyclic compound of the formula (2): ##STR13## wherein R 2  is a C 1-10  alkyl group, and R 3  is a hydrogen atom or a C 1-10  alkyl group. 
     
     
       5. A process for producing a cyclic compound of the formula (2): ##STR14## wherein R 2  is a C 1-10  alkyl group, and R 3  is a hydrogen atom or a C 1-10  alkyl group, Which comprises reacting a compound of the formula (4):   HO--CHR.sub.2 --CH.sub.2 COOH                              (4)     wherein R 2  is as defined above, with a compound of the formula (5):     X--CHR.sub.3 --CO--Y                                       (5)     wherein R 3  is as defined above, and each of X and Y is a halogen atom, to form a compound of the formula (6): ##STR15## wherein R 2 , R 3  and X are as defined above, and then subjecting the compound of the formula (6) to a ring closure reaction.   
     
     
       6. The process of claim 5, wherein compounds (4) and (5) are dissolved in a solvent and reacted in the presence of an amine compound to obtain compound (6), and compound (6) is then treated with alkali to obtain compound (2) by a ring closure reaction.